The present invention generally relates to a vacuum process apparatus, such as the vacuum process apparatus for coating thin films on photoelectric or semiconductor devices, and more particularly to an apparatus for sealing a vacuum chamber.
Vacuum process apparatus have been commonly used in many kinds of industries, applied to vacuum thin film coating process of workpieces such as liquid crystal substrates or semiconductor wafers. An operating environment inside the vacuum chamber must be maintained close to vacuum pressure. However, due to the different air pressures between the inside and the outside of vacuum chamber, the atmosphere is easy to leak into vacuum chamber through the entrance of workpiece.
An apparatus for sealing a vacuum chamber is disclosed in U.S. Pat. No. 6,120,611 xe2x80x9capparatus and method for hermetically sealing a chamberxe2x80x9d. It comprises a ball bearing and a photosensing element for reducing frictional force during hermetically sealing the chamber. It is a sealing apparatus installed at a cylindrical flange of the vacuum chamber for sealing the chamber hermetically, and the door is integrated with wafer loader so that the apparatus is uneasy to be used or installed individually.
The main object of the present invention is to provide an apparatus for sealing a vacuum chamber. By means of levers, transmitting rods and connecting rods, a second piston rod pushed forward by a short stroke cylinder on the frame elevator drives a plurality of direction-changing mechanisms to horizontally move a door for sealing a vacuum chamber, so that the door of large area or with high weight may be driven efficiently.
The secondary object of the present invention is to provide an apparatus for sealing a vacuum chamber. Because of parallel arrangement of the first piston rods for vertically elevating the door, the second piston rod for horizontally pushing the door and guide stems, the shell body can be designed as flat type. Therefore, according to the present invention, the apparatus for sealing a vacuum chamber has a super thin configuration, so that the moving space of robot arm is not interfered by the chamber door.
In accordance with the apparatus for sealing a vacuum chamber of the present invention, it comprises a plurality of long stroke cylinders, a frame elevator and a door. The frame elevator is combined with a plurality of first piston rods, at least a second piston rod and at least a guide stem. The long stroke cylinders linearly move the first piston rods and the frame elevator. The frame elevator is combined with at least a short stroke cylinder connecting with the second piston rod so the second piston rod moves along a parallel direction of guide stems. The second piston rod is connected to middle of a connecting rod through a lever and a transmitting rod. A plurality of direction-changing mechanisms are pivoted at the two ends of the connecting rod. It is preferable that the guide stem is fixedly combined with a support frame inside the shell body. The support fame has a plurality of narrow openings for limiting the movement of the direction-changing mechanisms so that a plurality of direction-changing mechanisms pivoted on the door horizontally push the door to seal the vacuum chamber under the vertical movement of the second piston rod.